Camping is a popular recreational activity enjoyed by many. Some people camp so that they may enjoy the outdoors, and others use camping as an inexpensive alternative to staying in a hotel.
Typically, campers sleep in a tent while camping. Tents are portable shelters made of lightweight, often waterproof, fabrics. Typically, a tent is a collapsible shelter of canvas or other material stretched over and sustained by a frame. Tents are used for camping outdoors or as temporary structures, and come in a variety of shapes and sizes. The most popular shape is the dome, or free standing, model. This model is easy to set up and does not require support from tree limbs or other objects—when the tent is set up, the entirety of the pole structure for the tent is attached to the tent. This feature permits the erected tent to be lifted by one or more campers, without the tent losing its shape. A rain fly may extend over the pole structure of the tent, and may be attached to the tent or may be staked to the ground. The campers may also stake the tent to the ground.
For many free standing tent structures, long poles are used that are flexible and that are extended between opposite corners of the tent. These poles are bent into arcs so that the ends can be attached to the tent corners or elsewhere along the outside edges of the floor of the tent. The fabric of the tent is attached along the arcs, such as by loops, hooks, or sleeves. The ends of the poles that are attached to the corners of the tent (or alternatively at the edges of the floor of the tent), coupled with the attachment of the walls and the roof of the tent to the central portion of the poles puts the tent fabric in tension, causing the tent fabric to take structure. After all of the poles are put in place, the tent fabric is tensioned to form the free standing tent structure.
Because a tent is often a closed structure, the air within the tent becomes stale. Condensation, stale air, and other odors are often expelled by providing tent ventilation. This ventilation can be provided, for example by keeping the doors slightly open or by having windows in the tent. More recently, tents have been designed so they have a mesh top and a rain fly that extends over the tent and is spaced from the mesh top by the pole structure for the tent. In theory, the air flows out of the tent through the mesh material at the top of the tent and into the area between the rain fly and the tent. This air then circulates out from under the rain fly.
Although the mesh and rain fly construction of tents works well, the rain fly does not always provide optimal ventilation. Often, the rain fly extends almost to the ground and if a breeze is not directed properly between the tent and the rain fly, the air and condensation may still accumulate underneath the rain fly and proper ventilation may not be supplied.
Another structure that is often used while camping is a shelter. In general, a shelter is a structure, typically a frame with poles, that includes a covering or canopy that provides protection from the rain, insects, and/or the sun. For camping, a shelter is typically made of fabric and foldable poles so that the shelter may be folded into a compact configuration for transport and storage. The shelter may or may not have walls, such as screen walls. The shelter may be, for example, set up over a picnic area, used adjacent to a tent as a storage area, configured to serve as protection from the rain, or used as a screened area to avoid insects.
Shelters also need ventilation. In general, shelters have an apex and two or more sides that extend down from the apex and that are attached to poles or another support. Condensation and stale air can accumulate under this apex. In addition, in warmer weather, the environment under an unvented shelter can become rather warm.